Transcript Polymer Overview - Nelson Research, inc

Polymeric Engineering Materials
an Overview
Craig E. Nelson - Consultant Engineer
Nelson Research, Inc.
2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com
Plastics and Elastomer Terminology
The terms "THERMOSETTING" and "THERMOPLASTIC" have been traditionally used to describe the
different types of plastic materials. A "THERMOSET" is like concrete. You only get one chance to liquify and
shape it. These materials can be "cured" or polymerized using heat and pressure or as with epoxies a chemical
reaction started by a chemical initiator.
A "THERMOPLASTIC", in general, is like wax; that is, you can melt it and shape it several times. The
"thermoplastic" materials are either crystalline or amorphous. Advances in chemistry have made the distinction
between crystalline and amorphous less clear, since some materials like nylon are formulated both as a crystalline
material and as an amorphous material.
Again, the advances in chemistry make it possible for a chemist to construct a material to be either thermoset or
thermoplastic. The main difference between the two classes of materials is whether the polymer chains remain
"LINEAR" and separate after molding (like spaghetti) or whether they undergo a chemical change and form a
three dimensional network (like a net) by "CROSSLINKING.“
Generally a crosslinked material is thermoset and cannot be reshaped. Due to recent advances in polymer
chemistry, the exceptions to this rule are continually growing. These materials are actually crosslinked
thermoplastics with the crosslinking occurring either during the processing or during the annealing cycle. The
linear materials are thermoplastic and are chemically unchanged during molding (except for possible degradation)
and can be reshaped again and again.
As previously discussed, crosslinking can be initiated by heat, chemical agents, irradiation, or a combination of
these. Theoretically, any linear plastic can be made into a crosslinked plastic with some modification to the
molecule so that the crosslinks form in orderly positions to maximize properties. It is conceivable that, in time, all
materials could be available in both linear and crosslinked formulations.
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Families of Plastics and Synthetic Resins
Acetal resins
Acetate cellulose (plastics) Acrylic
resins
Acrylonitrile-butadiene-styrene resins
Alcohol resins
polyvinyl Alkyd resins
Allyl resins Butadiene copolymers,
containing less than 50 percent
butadiene
Carbohydrate plastics
Casein plastics
Cellulose nitrate resins
Cellulose propionate (plastics)
Coal tar resins
Condensation plastics
Coumarone-indene resins
Cresol resins
Cresol-furfural resins
Dicyandiamine resins
Diisocyanate resins
Elastomers, nonvulcanizable (plastics)
Epichlorohydrin bisphenol
Epichlorohydrin diphenol Epoxy resins
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Ester gum
Ethyl cellulose plastics
Ethylene-vinyl acetate resins
Fluorohydrocarbon resins Ion exchange resins
Ionomer resins
Isobutylene polymers
Lignin plastics
Melamine resins
Methyl acrylate resins
Methyl cellulose plastics
Methyl methacrylate resins
Molding compounds, plastics
Nitrocellulose plastics (pyroxylin)
Nylon resins
Petroleum polymer resins
Phenol-furfural resins
Phenolic resins
Phenoxy resins
Phthalic alkyd resins
Phthalic anhydride resins
Polyacrylonitrile resins
Polyamide resins
Polycarbonate resins
Polyesters Polyethylene resins
Polyhexamethylenediamine adipamide resins
Polyisobutylenes
Polymerization plastics,
except fibers
Polypropylene resins
Polystyrene resins
Polyurethane resins
Polyvinyl chloride resins
Polyvinyl halide resins
Polyvinyl resins
Protein plastics
Pyroxylin Resins,
synthetic Rosin modified
resins
Silicone fluid solution
(fluid for sonar
transducers)
Silicone resins
Soybean plastics
Styrene resins
Styrene-acrylonitrile
resins
Tar acid resins
Urea resins
Vinyl resins
2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com
Chemical Resistant Resin-Polymer Families
Fluoropolymer - Hard Plastic
Teflon - Vespel
PVDF
Polycarbonate
Hydroxyl-Terminated Polybutadiene Resin
Furfuryl Alcohol Resin
Isophalic Polyester Resin
Fluoroelastomer - Rubbers – Very Soft Plastic - Paste
Viton, Kalrez, Chemraz
Elastomeric Bisphenol A Epoxy Vinylester
Dow 730
Parylene – Conformal Coating
poly-para-xylylene
Polyamide-imide (PAI)
Solvay TORLON
Thermoplastic Rubbers
Santoprene
Vinylester Resin – Hard Plastic
Methacrylated
Novalac – methacrylated Epoxy Vinylester
High Cross Linked Bisphenol A Epoxy Vinylester
Vipel F083
Bisphenol A Fummareate Polyester
Derakane 411
Vipel F282
Polyamide Film
Dupont Kapton
Polyphenylene Sulphide
HPV PPS Techtron
UHMW-PE Ultra High MW Polyethylene
HD-PE High Density Polyethylene
Chlorendic Polyester Resin – Hard Plastic
Hetron 197-3
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2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com
Fluoropolymers, Fluoroelastomers, Perfluoroelastomers Comparison
Fluoropolymers (also referred to as Fluorothermoplastics and
Fluoroplastics)
Fluoropolymers are high-performance polymers containing atoms of fluorine and are
unique because they perform well in a wide range of applications. They are defined by
their unusual resistance to chemicals & corrosion and their ability to withstand a wide
range of high temperatures. Fluoropolymers are extremely flexible and have excellent
anti-stick properties.
Disadvantages of Fluoropolymers
Application specific due to cost
Advantages of Fluoropolymers
Chemical resistant, operates in high temperatures, UV resistant, non-leaching, FDA
approved, USP Class VI compliant
Examples of Fluoropolymers
PTFE PVDF
FEP PEEK
PFA ETFE
ECTFE
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Fluoropolymers, Fluoroelastomers, Perfluoroelastomers Comparison
Fluoroelastomers (FKM)
Fluoroelastomers are a family of synthetic rubbers that can
be stretched extensively, and still return to their original
shape once the stretching is released. It is actually a
fluoropolymer that does not crystallize.
Disadvantages of Fluoroelastomers
very expensive
Advantages of Fluoroelastomers
chemical resistant, resistant to automotive and aircraft fuel,
FDA approved
Examples of Fluoroelastomers
Viton®
Dyneon®
Aflas®
Nelson Research, Inc.
2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com
Fluoropolymers, Fluoroelastomers, Perfluoroelastomers Comparison
Perfluoroelastomers –(FFKM)
Perfluoroelastomers polymers are made up of three or more monomers, in which
all hydrogen positions have been replaced by fluorine, the principal monomer
being tetrafluoroethylene, or TFE. This is the most chemically resistant elastomer
available and is effectively a rubber form of TFE
Disadvantages of Perfluoroelastomers
only available in O-ring and sheet form
very expensive
Advantages of Perfluoroelastomers
most chemically resistant of all elastomers
resistant to acids, caustics, amines, aldehydes, steam, and salt water
Examples of Perfluoroelastomers
Kalrez®
Chemraz®
Aflas®
Nelson Research, Inc.
2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com
Fluoropolymers, Fluoroelastomers, Perfluoroelastomers Comparison
Thermoplastics – sometimes referred to as Petroleum resins
Most of the worlds plastics are thermoplastics. Thermoplastic polymers melt
when heated and return to their original state when cooled again, unless they
were heated to a point above their decomposition temperature.
Disadvantages of Thermoplastics
higher creep
Advantages of Thermoplastics
less expensive due to fast cycle times
more complex designs are possible
wider range of properties due to copolymerization
Examples of Thermoplastics
PVDF
PTFE
PVC
Nelson Research, Inc.
2142 – N. 88th St. Seattle, WA. 98103 USA 206-498-9447 Craigmail @ aol.com